How I ported a Rails 2.3 app to 3.2

First I installed rails 3.2
gem install rails -v=3.2.0
Then I generated a new Rails app
rails new subcryption
Then I copied the whole of the app folder from my old app to the new one
Then I copied the config/database.yml from the old app to config/ in the new one
Then I altered the contents of the front page, index.html.erb, like this:
It was

Then I edited Gemfile, so it looks like this:
source 'http://rubygems.org'
gem 'rails', '>=3.2.0'
gem 'therubyracer'
gem 'rmagick'
gem 'gruff'
gem 'mysql'
gem 'sass', '~> 3.1.3'
gem 'coffee-script'
group :test do
gem 'turn', :require => false
end
Then
gem install bundler
bundle install --path=vendor/bundle
That updates your gems with the gems in the Gemfile and their dependencies
I always find routes.rb difficult. What I do, is make it as simple as possible, and
have the controller actions sort out what to do from the parameters that get passed from
the erb pages, through routes, to the controllers. Anyway it now looks like this:
Subcryption::Application.routes.draw do
root :to => 'main#index'
match 'main/show' => 'main#show'
match 'assets' => 'main#image'
end
and the controller sorts out the image drawing stuff. It used to have
two methods, image and weather (for the two pictures on the front
page of subcryption.com), but now it only has one, image, and it uses the
parameter 'what' (see index.html.erb above) to decide which image it is rendering:
def image
@blob = Graph.new
send_data (params[ :what ] == 'image' ? @blob.image : @blob.scene),
:disposition => 'inline',
:type => 'image/png',
:filename => @blob.file_name
end
Graph is a model, based on imagemagick and gruff. Some of it looks like this:
dada = [1,2,3,1,5,2,1,0,0,7,8,4,3,0,1,1,3,2,2,8,7,7,5,0,4,9]
g = Gruff::Line.new(dada)
g.x_axis_label = 'Years'
g.y_axis_label = 'Degrees'
g.marker_font_size = 16
g.data('temp', dada)
return g.to_blob
I copied the whole of public/images into app/assets/images, public/stylesheets into
app/assets/stylesheets, and public/javascripts into app/assets/javascripts.
Some of them don't need to be in both places, but some of them do.
This is all to do with the 'asset pipeline'. Why the asset pipeline can't look
in public/images etc. I don't know.
To run it, it's 'rails server' instead of 'script/server'.